Shutter structures are known and comprised of louver assemblies having control rods which permit the louvers to pivot in synchronism to a desired position from a closed position to an open position. Examples of such louver adjustment mechanisms are disclosed in U.S. Pat. Nos. 5,187,896, 2,309,354 and 2,037,176. A disadvantage of such louver adjusting mechanisms is that although some of these may provide adjustment to position a plurality of louvers at a desired angle, their mechanisms do not provide for the louvers to remain at that angle when subjected to wind pressure. Accordingly, depending on the wind orientation, it is conceivable that in a room some shutters which are positioned over a window opening facing the wind may be oriented at different angles or shut as compared with shutters of other window openings oriented differently with respect to the wind. This will affect the ventilation of a room or the amount of light which is desired to penetrate the particular room. These adjusting mechanisms are also difficult to assemble due to their many component parts and are difficult to repair. There is therefore a need to provide a louver assembly with an adjustment mechanism which can secure and maintain louvers at a desired angular orientation and which is simple to install and repair.